Fuel gauge and sender

[Mark D]

"drove it" - wow congrats!

 

Last week I bought one of these stainless sender units off ebay for my Chrysler, that has one wire, $60.  

 

It looks really good, but it has a couple of problems.  It goes from zero ohms to about 40.  Supposed to be 10 to 90.  And when I put it in a full tank, it read around 5/8.  As I drove it the next few days, the guage went up.  I bent the arm the other way and now the guage moves the right way as I burn the gas out of the tank, but I'm guessing it'll run out when the guage says 5/8.  I took the cap off the inside of the sender and instead of the cone of windings it's a flat winding plate.  Less wiring makes less resistance.

 

Now I need to find a way that will multiply the ohm reading by 2.25.  There's got to be some way to do that.  Any electrical engineers out there?  Could I just put a resistor in line? or parallel? 

[TodFitch]

Last week I bought one of these stainless sender units off ebay for my Chrysler, that has one wire, $60.  

 

It looks really good, but it has a couple of problems.  It goes from zero ohms to about 40.  Supposed to be 10 to 90.  And when I put it in a full tank, it read around 5/8.  As I drove it the next few days, the guage went up.  I bent the arm the other way and now the guage moves the right way as I burn the gas out of the tank, but I'm guessing it'll run out when the guage says 5/8.  I took the cap off the inside of the sender and instead of the cone of windings it's a flat winding plate.  Less wiring makes less resistance.

 

Now I need to find a way that will multiply the ohm reading by 2.25.  There's got to be some way to do that.  Any electrical engineers out there?  Could I just put a resistor in line? or parallel? 

 

Not an electrical engineer, but you can't extend the range by adding resistors either in series or in parallel. You could add a 10 ohm resistor in line to offset the output (change it from 0-40 to 10-50).

 

You say it has a "flat winding plate" so I assume it uses the old style resistance wire. Other than rewiring it, I don't know what your option is.

 

The newer universal senders seem to use a thick film screened "resistor card" which have an advantage that you can take a Dremel tool and remove resistive material to raise the resistance. By selecting where on the card you remove resistance you have the posibility of customizing the fuel level response curve. I took advantage of that to come up with a sender for my 1933 which uses a range of values no longer available: http://www.ply33.com/Repair/fuelsender2.html

[OldDad67]

I guess I'll answer my own question. I just recieved my new sender in the mail today. It appears to be of very good quality and certainly better than paying the $200.00 e-bay price for an old original. I'll test it before installation and try and keep everyone up to date on the results.

So today I hooked up my new stainless steel sending unit I purchased off e-bay and checked out 2 gas gauges I had and everything worked great. So if you need a new sending unit you don't have to pay 200+ dollars to get one. This is kinda fun answering my own questions!

 

[BobT-47P15]

 

Re my earlier post mentioning Tomsclassic on ebay..........i found this info on another forum when a poster was asking

about Toms.............so might try to see if it's indeed the right guy...........

 

 

Tom is one of the owners of Auto City Classic 800-828-2212

 

Link to Auto City site........http://www.autocityclassic.com/index.php?option=com_virtuemart&page=shop.browse&category_id=883&Itemid=64

 

May or may not be helpful, but perhaps worth a call.

[OldDad67]

 

Re my earlier post mentioning Tomsclassic on ebay..........i found this info on another forum when a poster was asking

about Toms.............so might try to see if it's indeed the right guy...........

 

 

Tom is one of the owners of Auto City Classic 800-828-2212

 

Link to Auto City site........http://www.autocityclassic.com/index.php?option=com_virtuemart&page=shop.browse&category_id=883&Itemid=64

 

May or may not be helpful, but perhaps worth a call.

BobT-47P15 I did buy it from Tom's Classics, seems like a very well made piece. I just hate the price gougers on e-bay that are asking 2 to 300 bucks for stuff. I guess it's my choice wheather I buy it or not, guess I'm just a cheap old fart.

 

[Robert Horne]

Last week I bought one of these stainless sender units off ebay for my Chrysler, that has one wire, $60.  

 

It looks really good, but it has a couple of problems.  It goes from zero ohms to about 40.  Supposed to be 10 to 90.  And when I put it in a full tank, it read around 5/8.  As I drove it the next few days, the guage went up.  I bent the arm the other way and now the guage moves the right way as I burn the gas out of the tank, but I'm guessing it'll run out when the guage says 5/8.  I took the cap off the inside of the sender and instead of the cone of windings it's a flat winding plate.  Less wiring makes less resistance.

 

Now I need to find a way that will multiply the ohm reading by 2.25.  There's got to be some way to do that.  Any electrical engineers out there?  Could I just put a resistor in line? or parallel? 

 

 

You may have good luck with a voltage reducer.

 

I am using a Ford fuel gauge, with my 38 Coupe's face on it,  a Datson sender unit, and a voltage reducer to 6 volt.

 

Has been fairly accurate....

[OldDad67]

You may have good luck with a voltage reducer.

 

I am using a Ford fuel gauge, with my 38 Coupe's face on it,  a Datson sender unit, and a voltage reducer to 6 volt.

 

Has been fairly accurate....

Thanks for the info Robert, I'm going to use a "Runtz" on my fuel gauge since the system will be 12 volts. I have have very good luck with the "Runtz" on my 52 Chevy hardtop fuel gauge. I tested my new sending unit with a 6 volts source. What year F--d fuel gauge did you use? I assume 12 volt.

[Robert Horne]

I believe the Ford fuel gauge I used was from the 1995 Ranger I junked.....